Double Patenting At The EPO: Settled Law, Evolving Practice?

The prohibition on double patenting at the European Patent Office (EPO) has long been recognised as a general principle of procedural law, notwithstanding the absence of any explicit provision in the European Patent Convention (EPC). While the Enlarged Board of Appeal has confirmed both the existence and the limits of that prohibition, recent developments under the EPO’s Convergence of Practice programme raise the question whether examination practice may now begin to edge beyond strictly identical subject-matter.

In March 2026, the Administrative Council of the European Patent Organisation approved a new “common practice as regards double patenting”.¹ Although formally non-binding, this document reflects a coordinated position among the EPO and participating national offices and is therefore likely to influence day‑to‑day examination going forward. The key issue is whether this common practice merely codifies existing law, or whether it signals a subtle – but potentially important –